The present invention relates to a sun visor for automobiles and in particular to a sun visor produced by blow molding of a plastic material.
Automobiles sun visors produced by blow molding of a plastic material, for example polyethylene, are well known. These sun visors may comprise, like the visors based, for example, on a net structure, the so-called vanity mirror, which is usually arranged in the passenger side sun visor, and which may simply be superimposed on the corresponding side of the sun visor or be attached thereto by a cavity prepared for such purpose.
Further to the vanity mirror, the sun visors generally comprise a retaining spring and a hanging bridge situated in corresponding ends of the sun visor. The purpose of the retaining spring is to receive the pivot pin of the bent support attached to the vehicle structure so that, when engaged, the sun visor may be moved about the pivot pin by a simple manual operation and occupy stable positions of use freely selected by the user. The hanging bridge may be engaged, in turn, to a support member also attached to the vehicle structure so that, once engaged, they provide the sun visor with an auxiliary point of support which helps to withstand possible mechanical overloads capable of affecting the engagement of the retaining spring and the pivot pin of the bent support and weakening their resistance to untimely movement.
As an example of a sun visor manufactured from a one-piece hollow body member blow molded from a plastics material comprising the above mentioned elements, there may be mentioned Spanish patent P 9100391. This patent describes a sun visor with the hollow body member formed at one end thereof with a through orifice defining a hanging bridge and which internally houses and retains at the opposite end a retaining spring which is accessible from the outside of the sun visor only through a pertinent opening.
In general, the sun visor hollow body members formed by blow molding of plastics materials have a limited mechanical strength, which, under normal conditions of use, easily causes deformation. To avoid this drawback, the hollow body members are generally provided with additional structural reinforcement members. In this regard, there may be mentioned those provided by said Spanish patent P 9100391 consisting basically of a filling contained inside said body member. The filing is formed by an appropriate plastics material, such as polyurethane. The filling of the one-piece hollow body member by plastics materials to increase the mechanical strength thereof and avoid deformation under normal conditions of use suffers as the main drawback from a high production cost which, obviously, makes the finished product more expensive.